posted by Lisa .
fill in the missing digits in as many ways as
possible so the number will be divisible by 6.
A number is divisible by 6 if it is divisible by 2 AND by 3
Clearly since the above number is even, it is divisible by 2, so all we have to worry about is the 3
A number is divisible by 3 if the sum of its digits is divisible by 3.
So far we have a sum of 5.
So adding 1 or 4 or 7 would leave the sum divisible by 3
so the missing digits could be 1, 4, or 7
(numbers are 312, 342, or 372, check to see if they divide by 6)